I've got a string like "foo\nbar", but depending on platform, that could become "foo\n\rbar", or whatever. I want to replace new lines with ", ". Is there a nice (php) regex that'll do that for me?
Try the regular expression (?:\r\n|[\r\n]):
preg_replace('/(?:\r\n|[\r\n])/', ', ', $str)
You dont want to use a Regex for a simple replacement like this. Regular string replacement functions are usually much faster. For the line break, you can use the OS aware constant PHP_EOL, e.g.
str_replace(PHP_EOL, ', ', $someString);
On Windows, this will replace \r\n. On Mac \r and on all other systems \n.
Wouldn't str_replace(array("\n", "\r"), "", $string) work?
Related
Basically, I have a string that I need to search through and remove every SECOND occurrence within it.
Here is what my string looks like ($s):
question1,answer1,answer2,answer3,answer4
question2,answer1,answer2,answer3,answer4
question3,answer1,answer2,answer3,answer4
Here is what my code currently looks like:
$toRemove = array("\n");
$finalString = str_replace($toRemove, "", $s);
As you can see, each line within my s string contains two \n between them. I would like to search through my string and only replace every SECOND \n so that my string ends up being:
question1,answer1,answer2,answer3,answer4
question2,answer1,answer2,answer3,answer4
question3,answer1,answer2,answer3,answer4
Is this possible? If so, how can I do it?
In your specific case, you may want to just replace two newlines with one newline:
$string = str_replace("\n\n", "\n", $string);
More complicated regex solutions could collapse any number of concurrent newlines:
preg_replace("/\n+/", "\n", "foo\n\nbar\n\n\n\n\nblee\nnope");
Adam's answer is correct for UNIX like systems but in Windows you can have different line endings. My Regex is a little bit rusty but I think this should work for UNIX and Windows.
$string = preg_replace('/[\n\r]{2}/', '\n', $string); Replace exact 2 line endings
$string = preg_replace('/[\n\r]+/', '\n', $string); Replace 1 or more line endings
If I assign a 2 lines value to a variable like this.
$tt = 'part 1
part 2 ';
and I echo it.
echo $tt;
My browser will display it on 2 lines and it's fine. But on the source page, the code will have it on 2 lines.
How can it get rid of this carriage return.
Since it',s not a chr(13) and a \r, these don't works.
echo str_replace(chr(13), '-', $tt);
echo str_replace('\r', '-', $tt);
Any idea?
It really depends on the environment you're in. In Windows a line break is \r\n. In *nix environments it's just \n.
echo str_replace("\r", "-", str_replace("\n", "-", $tt));
Simple way for Windows or Linux:
str_replace("\r\n", "-", $var);
On Linux, the \r\n still gets detected. Anything else suggested here is overkill (though not necessarily incorrect).
Keep in mind that you need to use double quotes when using special characters like \r or \n.
Edit:
If you want to be extra careful, you can use this instead:
str_replace(array("\r\n", "\n"), "-", $var);
You shouldn't need any extra overhead of using the char() function, for something like \r or \n.
You can try
str_replace(array(chr(13),chr(10)), "-", $tt);
I am attempting to remove some line breaks and spaces from a multiline string I have, such as the following:
Toronto (YTZ)
to
Montreal (YUL)
I tried doing:
$matched = preg_replace('/[\n]/', '', $string);
var_dump($matched);
but all it returns is:
Montreal (YUL)
I've tried all sorts of combinations of regular expressions, but it only ever seems to find what I specify, replace it, and display anything AFTER the matched expression.
I'm sure it's something simple, but I can't seem to figure it out.
Thanks in advance!
\n only represents "go to line" if it is between double quotes in PHP "\n"... Your regex should be "/[\n]/" not '/[\n]/'
Anyway, don't use a regular expression for that, but str_replace("\n",'',$string) instead. It's faster.
As Kash already noticed you, expression of new line in different OS can be different.
That's where PHP_EOL constant is used. This constant is defined depending on OS.
$string = str_replace(PHP_EOL, '', $string);
if string could be created on different machine, then it would be better to replace "\r" and "\n" separately
$string = str_replace(array("\r", "\n"), '', $string);
$str = preg_replace('/\n+(?=.)/', " ",
preg_replace('/^\s*/m', "",
$str));
Check this code here.
I have a text file that has the literal string \r\n in it. I want to replace this with an actual line break (\n).
I know that the regex /\\r\\n/ should match it (I have tested it in Reggy), but I cannot get it to work in PHP.
I have tried the following variations:
preg_replace("/\\\\r\\\\n/", "\n", $line);
preg_replace("/\\\\[r]\\\\[n]/", "\n", $line);
preg_replace("/[\\\\][r][\\\\][n]/", "\n", $line);
preg_replace("/[\\\\]r[\\\\]n/", "\n", $line);
If I just try to replace the backslash, it works properly. As soon as I add an r, it finds no matches.
The file I am reading is encoded as UTF-16.
Edit:
I have also already tried using str_replace().
I now believe that the problem here is the character encoding of the file. I tried the following, and it did work:
$testString = "\\r\\n";
echo preg_replace("/\\\\r\\\\n/", "\n", $testString);
but it does not work on lines I am reading in from my file.
Save yourself the effort of figuring out the regex and try str_replace() instead:
str_replace('\r\n', "\n", $string);
Save yourself the effort of figuring out the regex and the escaping within double quotes:
$fixed = str_replace('\r\n', "\n", $line);
For what it is worth, preg_replace("/\\\\r\\\\n/", "\n", $line); should be fine. As a demonstration:
var_dump(preg_replace("/\\\\r\\\\n/", "NL", 'Cake is yummy\r\n\r\n'));
Gives: string(17) "Cake is yummyNLNL"
Also fine is: '/\\\r\\\n/' and '/\\\\r\\\\n/'
Important - if the above doesn't work, are you even sure literal \r\n is what you're trying to match?..
UTF-16 is the problem. If you're just working with raw the bytes, then you can use the full sequences for replacing:
$out = str_replace("\x00\x5c\x00\x72\x00\x5c\x00\x6e", "\x00\x0a", $in);
This assumes big-endian UTF-16, else swap the zero bytes to come after the non zeros:
$out = str_replace("\x5c\x00\x72\x00\x5c\x00\x6e\x00", "\x0a\x00", $in);
If that doesn't work, please post a byte-dump of your input file so we can see what it actually contains.
$result = preg_replace('/\\\\r\\\\n/', '\n', $subject);
The regex above replaces the type of line break normally used on windows (\r\n) with linux line breaks (\n).
References:
Difference between CR LF, LF and CR line break types?
Right way to escape backslash [ \ ] in PHP regex?
Regex Explanation
I always keep searching for this topic, and I always come back to a personal line I wrote.
It looks neat and its based on RegEx:
"/[\n\r]/"
PHP
preg_replace("/[\n\r]/",'\n', $string )
or
preg_replace("/[\n\r]/",$replaceStr, $string )
I want to detect a carriage return or a newline character when a user enters data into a textarea. What is the best way to handle this? I've tried str_replace with escape characters but carriage returns and newlines are not detected.
OK, say I type the following into a textarea:
The summer was hot this year
but next year is supposed to be cooler.
I want to detect the CRs. In this case, there is one.
Newlines could be \r, \r\n, or \n, depending on the client.
$input = preg_replace('/\r\n?/',"\n",$input)
will standardize all of your newlines to "\n" regardless of where they came from.
You can do it like this with str_replace:
function replace_newline($string) {
return (string)str_replace(array("\r", "\r\n", "\n"), '', $string);
}
There are several ways how new line is stored.
Some systems use only "\n" some "\r" and some both "\r\n". You need to check for both "\r" and "\n"
Try the following. It's always worked a charm for me.
You need to replace \n AND \r, it's because a linux system and a windows system use different characters for newlines.
$input = str_replace(array("\n","\r"),'',$input);
Or check for chr(10) and replace on that
Have you tried preg_replace because that can be used for regex replacements and then you can replace using \n or \r or any combination you require although I believe str_replace should also work fine.
function replace_newlines($string) {
return preg_replace('/\r\n|\r|\n/', '', $string);
}